【正文】 超聲波實現(xiàn)無接觸測距的倒車雷達系統(tǒng)設(shè)計 摘 要 隨著整個國家生活水平的提高，購車族也日益增多，汽車早已成為人們生活的必需品，然而汽車給人們帶來方便快捷的同時，也出現(xiàn)了許許多多的交通事故，其中因倒車引起的剮蹭事件則數(shù)不勝數(shù)，給人們帶來了許多不必要的經(jīng)濟損失，盡管每輛車都有后視鏡，但是我們要知道后視盲區(qū)卻不可避免，針對這一問題，設(shè)計出一個響應(yīng)快、靈敏度高的倒車雷達勢在必行。 本文利用超聲波實現(xiàn)無接觸測距，設(shè)計出一種倒車雷達系統(tǒng)，本文主要是利用超聲波 穿透性強，衰減小，反射能力強等特點 ，將超聲波的測距原理與 STC89C52RC 單片機結(jié)合起來， 利用超聲波 的 發(fā)射與接收電路實現(xiàn)無接觸測距 。由于 環(huán)境溫度對超聲波波速 有 影響，使用 DS18B20 構(gòu)成的溫度測量電路，通過溫度補償法對速度進行校正 ，直接讀取溫度值， 從而 得出超聲波在某一溫度下的波速，測得并顯示距離，再根據(jù)顯示的距離控制蜂鳴器的發(fā)聲頻率。 論文在介紹超聲波測距的原理及發(fā)展的基礎(chǔ)上， 設(shè)計 STC89C52RC 單片機的接口控制電路，對溫度信號、超聲波發(fā)射與接收信號進行采集與控制，實現(xiàn)溫度補償與距離報警 ，通過比較多種發(fā)射及接收電路方案，對系統(tǒng)的誤差進行分析，得出了最合理的控制 方案，對系統(tǒng)的各個單元的原理及組成各系統(tǒng)電路的芯片原理進行介紹，論文也介紹了系統(tǒng)的軟件結(jié)構(gòu)，使系統(tǒng)更便攜、可靠和經(jīng)濟。 關(guān)鍵字： 超聲波測距；倒車雷達； STC89C52RC；溫度補償 計算機信息工程學院畢業(yè)論文 Design to noncontact ultrasonic ranging reversing radar system Abstract With the improvement of living standards across the country, car buyers are increasing, car has bee a necessity of life, cars bring the people convenient, but also appeared in many traffic accidents, which caused by reversing rub cut events are numerous, gave rise to a lot of unnecessary economic losses, even though vehicle has rearview mirror, but we need to know blind Spot was inevitable, to solve this problem, design a fast response, high sensitivity reversing radar imperative. In this paper, the use of ultrasound to achieve noncontact distance measurement, design a reversing radar system, this paper is the use of ultrasound perating strong, low attenuation, high reflectance characteristics, the principle of ultrasonic distance measurement with STC89C52RC microcontroller bines the use of ultrasound the transmitter and receiver circuits to achieve noncontact distance measurement. Ultrasonic velocity of the ambient temperature influence on the use DS18B20 temperature measurement circuit constituted by the temperature pensation method of the speed correction value is directly read the temperature, and thus the velocity of the ultrasonic wave at a certain temperature, and display the measured distance, then control the buzzer sound frequencies depending on the distance display. On the basis of the principles and development of ultrasonic ranging presentation on the design STC89C52RC microcontroller interface control circuit of the temperature signal, the ultrasonic transmitter and receiver signal acquisition and control, temperature pensation and distance alarm, by paring multiple transmit and receive circuit scheme, the error system were analyzed and the most reasonable control scheme, the principles of the system and each unit consisting of the system circuit chip principles are introduced, the paper also describes the software architecture of the system, making the system more portable, reliable and economical. Key words: Ultrasonic Ranging。 reversing radar。 STC89C52RC。 temperature pensation 計算機信息工程學院畢業(yè)論文 I 目錄 第 1 章 緒論 ........................................................ 1 課題設(shè)計的實用價值和理論意義 ....................................... 1 設(shè)計的實用價值 ................................................ 1 設(shè)計的理論意義 ................................................ 1 課題設(shè)計的國內(nèi)外應(yīng)用現(xiàn)狀 ........................................... 2 設(shè)計的國內(nèi)應(yīng)用現(xiàn)狀 ........................................... 2 設(shè)計的國外應(yīng)用現(xiàn)狀 ........................................... 2 論文的設(shè)計內(nèi)容及章節(jié)安排 ........................................... 3 論文的研究內(nèi)容 ................................................ 3 論文的章節(jié)安排 ................................................ 3 第 2 章 超聲波測距簡介 ............................................... 4 超聲波簡介 ......................................................... 4 超聲波及應(yīng)用 .................................................. 4 超聲波的基本性質(zhì) .............................................. 4 超聲波傳感器 ....................................................... 4 超聲波傳感器的分類及原理 ..................................... 4 超聲波傳感器的結(jié)構(gòu) ........................................... 5 超聲波測距原理及設(shè)計思路 ........................................... 6 超聲波測距原理 ................................................ 6 系統(tǒng)設(shè)計思路 .................................................. 7 第 3 章 系統(tǒng)元件介紹 ................................................. 9 單片機 STC89C52RC................................................... 9 超聲波測距模塊 .................................................... 11 計算機信息工程學院畢業(yè)論文 II 產(chǎn)品特點 ..................................................... 11 實物圖 ....................................................... 11 電氣參數(shù) ..................................................... 11 超聲波時序圖 ................................................. 12 溫度傳感器 DS18B20................................................. 12 LCD1602 液晶顯示器 ................................................. 13 液晶顯示器的優(yōu)點 ............................................. 13 液晶顯示器的優(yōu)點 ............................................. 13 LCD1602 基本參數(shù)及引腳功能 ................................... 13 第 4 章 系統(tǒng)硬件設(shè)計 ................................................ 16 超聲波測距系統(tǒng)結(jié)構(gòu) ................................................. 17 超聲波發(fā)射電路 .................................................... 17 超聲波接收電路 .................................................... 18 電源電路 .......................................................... 19 測溫電路 .......................................................... 19 顯示電路 .......................................................... 19 報警電路 .......................................................... 20 復位電路 .......................................................... 21 串行口通信電平轉(zhuǎn)換模塊 ............................................ 21 第 5 章 軟件設(shè)計 .................................................... 22 主程序設(shè)計 ........................................................ 22 子程序設(shè) 計 ........................................................ 23 距離計算子程序 ............................................... 23 顯示子程序 ................................................... 24